1. Field of the Invention
The present invention relates to a closed-type motor superior in dust and water resistance.
2. Description of the Related Art
In conventional closed-type motors, there have been problems of sealing treatments applied to a wire-drawn portion of a lead wire in a motor case. In the past, as structures in which to seal a clearance between an opening portion of a case and a lead wire, the following have been, for example, introduced: 1) Flow-type silicone rubber is inpoured into the clearance so as to seal the opening portion of the case and the lead wire; and 2) A double-tube bush is fitted into the opening portion of the case, the lead wire is then inserted into an inner tube of the double-tube bush, a tip of a tube that covers the lead wire is inserted between the inner tube and an outer tube of the double-tube bush, and the outer tube and the tube are fixed with a linkage band. See, for example, Japanese Patent Application Laid-Open No. 2002-34199 (hereinafter referred to as Patent Document 1). Still further, a structure using a water-resistant connector header at the wire-drawn portion of the lead wire pulled out from the case has also been introduced. With this structure, the clearance between the opening portion of the case and the lead wire can be eliminated.
However, in the structure where the clearance between the opening portion of the case and the lead wire is sealed with the flow-type silicone rubber, especially in a case where a plurality of the lead wires are used, clearance tends to be produced between each of the lead wires whereby it may be difficult to keep sealing qualities even. On the other hand, in the structure disclosed in the Patent Document 1, it may not be easy to ensure a good sealed condition between the case and the bush, and a rigid resin-made tube with high hardness may be required in order to prevent the tube from being damaged by the binding band whereby handling of the lead wire (such as bending) may be subjected to some restrictions. Furthermore, in the structure where the water-resistant connector header is used, it may ensure a stable water-resistant quality; however, the water-resistant connector header tends to be expensive, and the case needs to be enlarged in order to house the connector head.